Grinding-roll.



PATENTED AUG. s, 1905.

, G. B. NUTT. GRINDING ROLLS. APPLICATION FILED AUG.17,1904.

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PATENTED AUGi 8, 1905.

G. B. NUTT. GRINDING ROLLS. APPLIOATION FILED AUG.17.1904.

2 SHEETS-SHBET 2.

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WITNESSES UNITED STATES PATENT OFFIOE.

GEORGE B. NUTT, OF PITTSBURG. PENNSYLVANIA.

GRlNDlNG-ROLL.

4 Speccation of Letters Patent.

Patented Aug. 8, 1905.

Application filed August 17, 1904. Serial No. 221.038.

Rolls; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to grinding or crushing rolls, and more especially to rolls for the fine grinding of ores, cement, or other pulverizable material, although the invention is applicable to grinding-mills of various kinds or to rolls for crushing sugar-cane or other substances.

Heretofore there have been used crushingrolls consisting of a set of rolls with sheaves mounted on the axes thereof, together with an endless rope or band passing around said sheaves and having a Huid-pressure cylinder connected to the bight thereof, so as to tighten the rope and draw the rolls toward each other and giving the requisite pressure for crushing the material.

My invention relates to the foregoing type of crushing-rolls; and its object is to increase the crushing or grinding capacity thereof.

To this end it consists, generally stated, in a double set of rolls and a single endless rope or band for giving the requisite crushing pressure for both sets of rolls'.

The invention also consists in the specific arrangement of parts and details of construction hereinafter described and claimed.

In the accompanying' drawings, Figure 1 is a plan view of my improved rolls. Fig. 2 is side elevation thereof. Fig. 3 is a vertical section on the line 3 3, Fig. 1. Fig. 4 is a similar section on the line 4 .4, Fig. 1; and Fig. 5 is a side elevation showing a modification.

In the drawings, 1 represents suitable housings or frames for the rolls. In these housings are mounted three shafts 2, 3, and 4, re-v spectively. On each of the shafts 2 and 3 are mounted two crushing or grinding rolls 5 5 and 6 6, thus forming, in effect, a double crushing-mill. These rolls may be provided with smooth faces; but preferably the faces will be roughened, iiuted, or corrugated in any suitable way. The grinding-faces of these rolls may be solid with the bodies thereof, but preferably they are formed as chilled segments bolted or otherwise suitably secured to the bodies of the rolls. The journal-boxes 8 of the shafts 2 and 3 are of such size that they contact with each other, and thus hold the faces of the rolls 5 5 and 6 6 slightly apart and prevent said faces from coming into contact when no material is passing through the rolls. To take up wear of the journals and the like, shims or adjustable wedges 7 may be placed between these journal-boxes.

On the shaft 2, between the two crushingrolls thereon, are a series of sheaves 10, and on the shaft 4 is a similar series of sheaves 11.

Passing around the sheaves 10 and 11 is an endless rope or band 12, the bight of which passes around a sheave 13, connected to the piston-rod of a power-cylinder 14, which is adapted to be actuated by any elastic iiuid, such as compressed air or steam.` of this po wer-cylinder is to tighten the rope 12 to draw the shafts 4 and 2 together. The rope 12, passing around the plurality of sheaves, acts on the principle of a compound block and tackle and multiplies the power exerted by the cylinderv by the number of sheaves or loops in the rope, as will be readily understood. The pressure exerted by the cable 12 on the shaft 4 is communicated to the shaft 3 through the medium of rims or collars 16 and 17 on the shafts 3 and 4, respectively. Preferably a pair of collars are provided on each shaft, one on either side of the rope 12. As a consequence the pressure exerted by the powercylinder is communicated from the sheaves 11 on the shaft 4 to the shaft 3, thus holding the crushingrolls toward each other. The extrashaft 4 is necessary, because if the sheaves 11 were placed directly on the shaft 3 the size of said sheaves would have to be materially reduced in order to give suiiicient clearance from the sheaves on the shaft 2, and at the same time the straight portions of the ro pe between said sheaves would be so short as to have practically no elasticity, thus increasing the liability of breaking the same in case a non-crushable substance should pass through the rolls. i

The sheaves on one of the shafts 2 or 3 are independent of each other and loosely mounted on said shaft, the drawings showing the sheaves 10 loose on the shaft 2. The sheaves 11 likewise may` be independent and loose on the shaft 3; but this is not necessary, as the sheaves necessarily rotate-with the shafts, and as a consequence the sheaves on one shaft may be formed integral andkeyed directly thereto. The sheaves 11 are so-shown. The sheaves 10 are independent and rotatable in order to permit the rope to adjust itself, as must occur The actionv whenever the crushing-rolls advance towardv or recede from each other, these loose sheaves having rotary movement independent of each other and moving with the cable as it slackens or tightens. If both sets of sheaves were fast on their shafts, the sheaves would have to slip on the cable whenever the latter slaclrened or tightened.

The rolls may be driven in any suitable way, such as connecting to the shaft 2 a beltpulley 20 or other driving means. The other roll may be driven either by friction or by connected gearing, as desired.

In Fig. 5 I have shown a modification in which in place of a power-cylinder 14 I employ a suitable weight 21, the same being suspended from a clevis 22, carrying the guide-sheave 13 in the bight of the rope 12, the bight first passing over suitable guidesheaves 23. The weight 21 rests upon a cushioning-spring 24, the object of which is to allow for any sudden strain on the cable, such as occurs when a-large or non-crushable substance enters the rolls. The weight itself has such inertia that it might not yield to such sudden strain; but the spring will yield, and thus considerably reduce liability of injuring the rolls or breaking the rope.

In the operation of my rolls the material is fed between the rolls 5 5 and 6 6 in the ordinary way. As long as the rolls are ruiming empty the journal-boxes 8 of the two rollshafts will contact and prevent the crushingfaces of the rolls from touching, and while so running idle practically no friction will be exerted on the journals of the rolls. The introducing of the material between the faces of the crushing-rolls will separate them, thus exerting a tension on the rope 12, which is counterbalanced by the iuid-pressure cylinder 14 or weight 21, as the case may be. This counterbalancing load gives the necessary pressure for crushing the material between the rolls, and by reason of the compound block-and-tackle arrangement of the cable 12 and sheaves 10 and 11 the power thereof is greatly multiplied. For instance, if ten sheaves are used on each shaft and the power cylinder or weight give a pull of two thousand pounds on the bight of the rope 12 this pull will be increased at the crushing-rolls 5 5 and 6 6 practically ten times,thus givinga pressure of practically twenty thousand'pounds at said rolls. During thev crushing operation there will be practically no friction on the bearings of the shafts 2, 3, or 4, except possibly on the bearingsof the shaft 2, this being due to the fact that the rope will pull all of the rolls over against the end brasses of this end shaft.y

y It will be observed that only a single cable is employed and that the loops thereof are arranged centrally with Vreference to the rollaxes and that this one cable suffices to give the necessary pressure for two sets of crushing-rolls. In this way the capacity of the mill is very greatly increased.

If desired, other crushing-rolls might be placed on the shaft 4, thus giving three rolls for each set. Other modifications may also be made without departing from the spirit of my invention.

What I claim is- 1. In grinding or crushing rolls, the combination of a plurality of shafts, two rolls on each of two of said shafts, a setof sheaves supported on each of two of said shafts and in line with each other, an endless rope or band connecting said set of sheaves, said sheaves being so located that said rope or band lies between the pair of rolls on each of the two shafts, and means for exerting a pull on said rope or band.

2. In grinding or crushing rolls, the combination of a plurality of shafts, two rolls on each of two of said shafts, aset of sheaves supported on each of two of said shafts and in line with each other, an endless rope or band connecting said sets of sheaves, said sets of sheaves being so located that said rope or band lies between the p air of rolls on the two shafts and the sheaves of one of said sets being independently rotatable, and means for exerting a pull on said rope or band.

3. In grinding or crushing rolls,.the combination of a plurality of shafts, two rolls on each of two of said shafts, a set of sheaves supported on each of two of said shafts and in line with each other, an endless rope or band connecting said sets of sheaves, said sheaves being so located that the rope or band lies between the pair of rolls on each of the two shafts, a movable sheave acting on a bight of said rope or band, and constantly-acting means exerting a pull on said movable sheave.

4. In grinding or crushing rolls, the combination of a plurality of shafts, two rolls on each of twowof said shafts, a set of sheaves supported on each of two of said shafts and in line with each other, an endless rope or band connecting said sets of sheaves, said sheaves being so located that said rope or band lies between the pair of rolls on each of the two shafts, and a piston moved by elastic fluid under pressure and acting on a bight of said rope or band.

5. In grinding or crushing rolls, the combination of three shafts, housings therefor, a pair of crushing-rolls on one end shaft and also on the middle shaft, sheaves on said end shaft between the pair of rolls thereon, sheaves on the other end shaft, an endless rope or band connecting said sheaves, and means for exerting apull on said rope or band.

6. In grinding or crushing rolls, the combinationof three shafts, housings therefor, a pair of crushing-rolls on one end shaft and also on the middle shaft, sheaves on the said end shaft between the pair of rolls thereon, sheaves on the other end shaft, one set of said sheaves being independent of'each other and loosely mounted on the shaft, an endless rope or band connecting said sheaves, and means for exerting a pull on said rope or band.

7. In grinding or crushing rolls, the combination with three shafts, housings therefor, a pair of crushing-rolls on one end shaft and also on the middle shaft, sheaves on the said end shaft between the pair of rolls thereon, sheaves on the other end shaft, an endless rope or band connecting said sheaves, a movable sheave acting in the bight of said rope or band, and a piston moved b v elastic fiuid under pressure acting on said movable sheave.

8. In grinding or crushingrolls, the combination of three shaft's, housings therefor, crushing-rolls on one end shaft and also on the middle shaft, coacting pressure-transmitting collars on the other end shaft and on the middle shaft, sheaves on the two end shafts, an

endless rope or band connecting said sheaves, A

and means for exerting a pull on said rope or band.

9. In grinding or crushing rolls, thecombination of three shafts, housings therefor, rolls on one end shaft and also on the middle shaft, coacting pressure-transmitting collars on the other end shaft and on the middle shaft, sheaves on the two end shafts, the sheaves on one of said shafts being independent and loose on said shaft, an endless rope or band connecting said sheaves and means for exerting a pull on said rope or band.

10.- In grinding or crushing rolls, the combination of three shafts, housings therefor, two crushing-rolls on one end shaft and also on the middle shaft, sheaves on the said end shaft between the rolls thereon, sheaves on the other end shaft, coacting pressure-transmitting collars on the last-named end shaft and onv the middle shaft, sheaves on the two end shafts, an endless rope or band connecting said sheaves, and means for exerting a pull on said rope or band.

l1. In grinding or crushing rolls, the combination with three shafts, housings therefor, two crushing-rolls on one end shaft and also on the middle shaft, coacting pressure-transmitting collars on the other end shaft and on the middle shaft, sheaves on the two end shafts, the sheaves on one shaft being independent of each other and loosely mounted on said shaft, an endless rope or band connecting said sheaves, and means for exerting a pull on said rope or band.

12. In grinding or crushing rolls, the combination of three shafts, housings therefor, two crushing-rolls on one end shaft and also on the middle-shaft, coacting pressure-transmitting collars on the other end shaft and 0n the middle shaft, sheaves on the two end shafts, th'e sheaves on one end shaft being keyed thereto and those on the other end shaft being independent and loose thereon, an endless rope or band connecting said sheaves, and means for exerting a pull on said rope or band.

In testimony whereof I, the said GEORGE B. NUTT, have hereunto set my hand.

Witnesses:

ROBERT` C. ToTTEN, Gr. KREMER. 

